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US4851079A
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Producing lithium niobate waveguide structures
Assignee: BT&D Technologies Ltd
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Filing: 1986-12-17
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Granted: 1989-07-25
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Expires: 2006-12-17
Abstract
Abstract An improved method producing a lithium niobate waveguide device is described, and comprises; (i) providing an optical waveguide path on a lithium niobate substrate; (ii) depositing a layer of dielectric material on the substrate; (iii) depositing a layer of conducting material on the dielectric layer; (iv) defining one or more electrode tracks on the conducting layer using a suitable mask; and (v) dry etching using an auto-registered process to remove the unmasked regions of the conducting layer and dielectric layer using a suitable etching medium.
Inventors
- 👤 Richard C. Booth
- 👤 Alan R. Beaumont
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 03:19
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/10; G02B6/12; G02B6/13; G02B6/136
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
146 words
A method of producing a lithium niobate waveguide device, the method comprising the steps of (i) providing an optical waveguide path in the surface of lithium niobate substrate; (ii) depositing a layer of dielectric material on the substrate to directly cover at least a portion of said waveguide; (iii) depositing a layer of conducting material on the dielectric layer; (iv) defining electrode tracks on the conducting layer using a suitable etch mask which mask covers the portions of the conducting layer which are to become the electrodes; and (v) dry etching using an auto-registered process to remove the unmasked regions of the conducting layer and to remove the dielectric layer beneath the unmasked regions of the conducting layer using a suitable etching medium such that said electrodes are formed isolated from each other to the extent that said electrodes have no interconnection via said dielectric material.
Claim 2
Independent Claim
146 words
A method of producing a lithium niobate waveguide device, the method comprising the steps of (i) providing an optical waveguide path in the surface of lithium niobate substrate; (ii) depositing a layer of dielectric material on the substrate to directly cover at least a portion of said waveguide; (iii) depositing a layer of conducting material on the dielectric layer; (iv) defining electrode tracks on the conducting layer using a suitable etch mask which mask covers the portions of the conducting layer which are to become the electrodes; and (v) dry etching using an auto-registered process to remove the unmasked regions of the conducting layer and to remove the dielectric layer beneath the unmasked regions of the conducting layer using a suitable etching medium such that said electrodes are formed isolated from each other to the extent that said electrodes have no interconnection via said dielectric material.
Claim 3
Dependent Claim
18 words
A method according to claim 1 wherein the etching process in step (v) is a plasma etching process.
Claim 4
Dependent Claim
25 words
A method according to claim 1 or 2 wherein the etching medium is self-stopping in that it does not substantially erode the lithium niobate substrate.
Claim 5
Dependent Claim
15 words
A method according to claim 1 or 2 wherein the etching medium comprises carbon tetrachloride.
Claim 6
Dependent Claim
23 words
A method according to claim 1 or 2 wherein as a part of step (ii), the dielectric material is further prepared by annealing.
References Cited (Backward Citations)
US4403827A
Cited
US4598039A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-07-24 | 1993-01-23 | 1993-07-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-07-24 | 1997-01-23 | 1997-07-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-07-24 | 2001-01-23 | 2001-07-25 | $7700.00 | Window Closed / Lapsed |